A Numerical Simulation of a Long-Track EF5 Tornado Embedded Within a Supercell

A CM1 model simulation of a supercell thunderstorm and its attendant long-track EF5 tornado is described. The model was run within a 120 x 120 x 20 km domain. An inner isotropic mesh with 30 meter grid spacing within a 60 x 60 x 10 km domain was used and the mesh was stretched to the boundaries outside this inner domain. The model is initiated with an atmospheric sounding from a 1 hour RUC forecast located off the right flank of the supercell that spawned the Calumet-El Reno-Piedmont-Guthrie tornado of May 24, 2011. The tornado that forms lasts for over a hour with near-surface winds as high as 130 m/s, extends high up into the storm, and has an two-celled structure. In this poster we will present an overview of the simulated storm and tornado and look at the conditions that led to the tornado's longevity.